The effects of different restorative materials on the detection of approximal caries in cone-beam computed tomography scans with and without metal artifact reduction mode.

OBJECTIVES: The aim of this study was to investigate the influence of artifacts produced by different restorative materials on the detection of approximal caries in cone-beam computed tomography (CBCT) scans with and without the application of an artifact-reduction (AR) option. STUDY DESIGN: Ninety-eight noncavitated premolar and molar teeth were placed with approximal contacts consisting of 2 sound or carious teeth and 1 mesial-occlusal-distal restored tooth with resin-modified glass-ionomer cement (RMGIC), amalgam, composite, ceramic-based composite (CBC), or computer-aided design-computer-aided manufacturing (CAD-CAM) zirconia materials in between. The teeth were scanned with a CBCT system with and without the AR option. Images were evaluated by 2 observers. The teeth were histologically evaluated, and sensitivity, specificity, and areas under the receiver operating characteristic (ROC) curve were calculated according to the appropriate threshold. RESULTS: Specificity and sensitivity values for contact surfaces ranged from 0-48.39 and 82.93-98.40, respectively. The AR option affected (P < .05) approximal caries detection of the amalgam, composite, CAD-CAM, and CBC groups in contact surfaces and composite and RMGIC groups in noncontact surfaces. CONCLUSION: Artifacts produced by different restorative materials could affect approximal caries detection in CBCT scans. Use of the AR option with CBCT scans increases the accuracy of approximal caries detection.

The combined occluding effect of sodium fluoride varnish and Nd:YAG laser irradiation on dentinal tubules-A CLSM and SEM study.

The purpose of this study is to evaluate the dentinal tubule occlusion potential and penetration of Clinpro® White Varnish (5% sodium fluoride + tri-calcium phosphate) in the presence or absence of Nd:YAG laser. Seventy-five dentin samples collected from 38 freshly extracted human molars were randomly divided into five groups (n = 15). Groups A, B, D, and E were varnished with Clinpro, whereas group C (no treatment) served as the control group. Groups B and E were further irradiated with Nd:YAG laser (1.5 W, 10 Hz, 1 min). All study groups were subjected to pH cycling (kept in 0.3% citric acid 5 min/day for 5 days). Groups A, B, and C were evaluated for tubule occlusion using scanning electron microscopy. Groups D and E were evaluated for penetration with confocal laser scanning microscopy (SEM). Non-parametric Kruskall-Wallis and Dunn's statistical tests were used for analysis of SEM results. The penetration depths were analyzed with one-way ANOVA followed by Fisher's Least Significant Difference tests. Tubular occlusion of groups A and B were significantly greater than group C (p < 0.05). Tubular occlusion of group B were significantly greater than group A (p < 0.05). Penetration depth for group D was significantly greater than group E (p < 0.05). Laser application improved the tubular occlusion capacity of Clinpro. Contrary, laser reduced the penetration of Clinpro. SCANNING 38:619-624, 2016. © 2016 Wiley Periodicals, Inc.

Effect of fibre-reinforced composite on the fracture resistance of endodontically treated teeth.

The aim of this study is to evaluate the fracture resistance of root-filled teeth restored with fibre-reinforced composite (everX posterior). Fifty mandibular molars were divided into five groups (n = 10). Group 1: no treatment was applied (intact teeth). Group 2-5: canals were prepared and root filled. Group 2: no coronal restoration was placed. Group 3: teeth were coronally restored with composite. Group 4: composite restorations were performed following polyethylene fibre insertion at the cavity base. Group 5: composite resin placed over everX posterior. After thermocycling (5-55°C, 5000×), fracture resistance was measured. Mean force load for each sample was recorded in Newtons (N). Results were statistically analysed with one-way analysis of variance and post hoc Tukey's tests. The mean force required to fracture samples and standard deviations are as follows: group 1: 2859.5 ± 551.27 N, group 2: 318.97 ± 108.67 N, group 3: 1489.5 ± 505.04 N, group 4: 1958.3 ± 362.94 N, group 5: 2550.7 ± 586.1 N. everX posterior (group 5) was higher than groups 2, 3 and 4 (P < 0.05). There were no significant differences between everX posterior and intact teeth (P > 0.05). Placing fibre-reinforced composite under composite increased the fracture strength of root-filled teeth to the level of intact teeth.

Color stability and surface roughness of polished anterior restorative materials.

The purpose of this study was to investigate the effects of different finishing-polishing techniques on the color stability and surface roughness of various anterior restorative materials after staining. A composite, a compomer, and a resin-modified glass ionomer were used to prepare 120 specimens. Specimens were divided into subgroups: polishing discs, liquid polishing material, aluminium oxidebonded discs, and control. The specimens were stained in a coffee solution. Color parameters (L*a*b*) and surface roughness before and after staining were measured. The color was affected by the material type (p<0.05) and finishing-polishing systems (p<0.05). The composite showed the highest color stability; however, the color differences of all groups were visible even to the nonskilled operator. The Ra values did not significantly change after staining for any of the restorative groups (p>0.05). The finishing-polishing systems had an effect on color after storing in staining solution.

Age estimation for dental patients using orthopantomographs.

OBJECTIVES: The aim of this study was to conduct age estimates for dental patients using orthopantomographs (OPGs). The OPGs were selected by an independent author with respect to criteria and evaluated by two independent dentists. The results were compared to chronologic ages. The reliability of the estimates, concurrently made by the two independent dentists using OPGs, was also evaluated. METHODS: In this retrospective study, the OPGs of 238 Turkish individuals of known chronological age, ranging from 1 to 60 years, were measured. Patients were then classified. Radiographs were evaluated by two independent dentists and age estimation was achieved according to the decades. RESULTS: The truest age estimates made by the dentists were in the 1-10 years age range (89.6%), the most inaccurate age estimates were in the 41-50 years age range (41.7%). Results indicate that the accuracy of age estimation diminishes with age. CONCLUSIONS: Despite the variations related to the practitioners, in this study, there were no significant differences in age estimations between the two participant practitioners. Age estimation through evaluating OPGs was the most accurate in the first decade and the least in fourth decade. It can be concluded that OPGs are not adequate for accurate age estimation.